Lexus LX470 2002-06

Alternator

Print

Diagnosis & Testing



Alternator Load Test
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Connect a voltmeter and ammeter to the charging circuit as follows:
    1. Disconnect the wire from terminal B of the alternator, and connect it to the negative (-) tester probe of the ammeter.
    2.  
    3. Connect the positive (+) tester probe of the ammeter to terminal B of the alternator.
    4.  
    5. Connect the positive (+) tester probe of the voltmeter to terminal B of the alternator.
    6.  
    7. Ground the negative (-) tester probe of the voltmeter.
    8.  

  4.  
  5. With the engine running at 2,000 rpm, turn on the high beam headlights and set the heater blower switch to HI.
  6.  
  7. Check the reading on the ammeter. Standard amperage: 30 A or more
  8.  
  9. If the ammeter reading is less than the standard amperage, repair the alternator.
  10.  

Alternator No-Load Test
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Connect a voltmeter and ammeter to the charging circuit as follows:
    1. Disconnect the wire from terminal B of the alternator, and connect it to the negative (-) tester probe of the ammeter.
    2.  
    3. Connect the positive (+) tester probe of the ammeter to terminal B of the alternator.
    4.  
    5. Connect the positive (+) tester probe of the voltmeter to terminal B of the alternator.
    6.  
    7. Ground the negative (-) tester probe of the voltmeter.
    8.  

  4.  
  5. With the engine running from idling to 2,000 rpm, check the reading on the ammeter and voltmeter.
  6.  
  7. With no load on the system, the amperage should be 10 A or less, and the voltage should be 13.2-14.0 volts.
  8.  
  9. If the voltmeter reading is more than the standard voltage, replace the voltage regulator.
  10.  
  11. If the voltmeter reading is less than the standard voltage, check the voltage regulator and alternator.

    Click image to see an enlarged view

    Fig. Connecting voltmeter and ammeter for alternator testing

  12.  

Installation



  1. Install or connect the following:

    Alternator. Tighten the fasteners to 29 ft. lbs. (39 Nm).
     
    Alternator harness connectors
     
    Power steering pump pulley
     
    Radiator
     
    Engine under cover
     
    Accessory drive belt
     
    Negative battery cable
     

  2.  
  3. Fill the cooling system.
  4.  
  5. Start the engine and check for leaks.
  6.  

Removal & Installation



  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable
     
    Accessory drive belt
     
    Engine under cover
     
    Radiator
     
    Power steering pump pulley
     
    Alternator harness connectors
     
    Alternator
     

  6.  

  1. Before servicing the vehicle, refer to the precautions section.
  2.  
  3. Drain the cooling system.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable
     
    Accessory drive belt
     
    Engine under cover
     
    Radiator
     
    Power steering pump pulley
     
    Alternator harness connectors
     
    Alternator
     

  6.  

To install:

  1. Install or connect the following:

    Alternator. Tighten the fasteners to 29 ft. lbs. (39 Nm).
     
    Alternator harness connectors
     
    Power steering pump pulley
     
    Radiator
     
    Engine under cover
     
    Accessory drive belt
     
    Negative battery cable
     

  2.  
  3. Fill the cooling system.
  4.  
  5. Start the engine and check for leaks.
  6.  

  1. Before servicing the vehicle, refer to the precautions section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Remove the drive belt.
  6.  
  7. Disconnect the 2 oil cooler lines from the fan shroud, remove the fan shroud.
  8.  
  9. Remove the 4 nuts and remove the fan with the fluid coupling.
  10.  
  11. Disconnect the vane pump assembly.
  12.  
  13. Disconnect the alternator wiring.
  14.  
  15. Remove the nuts and bolts and remove the alternator.
  16.  

To install:

  1. Install the alternator. Tighten the bolt to 29 ft. lbs. (39 Nm), the upper nut to 29 ft. lbs. (39 Nm) and the side nut to 12 ft. lbs. (16 Nm).
  2.  
  3. Attach the alternator wiring.
  4.  
  5. Install the vane pump assembly.
  6.  
  7. Install the shroud and fluid coupling together and tighten shroud bolts. Tighten the fan coupling nuts to 21 ft. lbs. (29 Nm).
  8.  

 
label.common.footer.alt.autozoneLogo